The head of the National Security Agency delivered a vigorous defense Wednesday of his agency's collection of Americans' phone records for counterterrorism purposes, asserting that the program was helpful in investigations of…

The news that Microsoft co-founder Bill Gates now says it was a mistake to long ago force Windows PC users to type "Ctrl-Alt-Delete" at start-up is getting tons of attention because his public mea culpas are rather rare.

Bringing "common sense" to artificial intelligence is one of the biggest challenges in computer science: It entails equipping computers with the shared knowledge that humans use to infer meaning, make connections, and communicate…